Stretcher press



Sheet-s-Sheet l My 18, 1950 w. A. WEIGHTMAN STRETCHER PRESS Filed Dec.13, 1944 W. A. WEIGHTMAN `July 1s, 195o STRETCHER PRESS `Fi1ed nec. 15,1944 2 Sheets-Sheet 2 1 INVENToR WilumAM/eghman 7. Zwzvmm uw O -1L/WIFI:

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A TTORNE Y Patented July 18, 1950 STRETCHER PRESS William A. Weightman,Philadelphia, Pa., as-

signor to The Budd Company, Philadelphia, Pa., a corporation ofPennsylvania Application December 13, 1944, Serial No. 567,983

7 Claims. (Cl. 153-32) The invention relates to astretcher press andmore particularly to a machine of this type adapted for simultaneouslybending and stretching proles into curved forms.

Among the objects of the invention is a machine of the indicated typewhich is easily operated and which allows the production of a greatvariety of shapes including shapes with curvatures in more than oneplane. y

Another object of the invention is amachine'ljg) of the indicated typewhich can easily and speedily be adapted or changed to the production ofdifferently shaped articles.

The aforesaid objects and other objects and advantages are achieved' bya machine having `pairs of power driven independently movable theembodiment illustrated in the attached 30 drawings and described in thefollowing.

In the drawings:

Figure 1 is a plan view of a machine showing diagrammatically thecontrol circuits for the r different movable elements, certain partsbeing broken away; f

Figure 2 is a section on a larger scale along lline 2-2 of Figure 1`withone of the armsrswung about 90 from the positionshown inFigure 1;

Figure 3 is a section throughone of the arms 30 along line 3-3 of Figure2 on a still larger scale; and

Figure 4 is a fragmentary section along line 4-4 of Figure 1 on a scalelarger .than thatWil of Figure 2. Y A l V e#SI5 A floor I9 supports abase plate II. Part of the plate II coversy a well I2 in the floor II)the side walls of which are formed by beams I3. An upright wall I4 hasits lower margin secured to a reinforcement l5 of the base plate and itsw40 upper margin to a table top IB.. Webs I1, I8 and I9 interbrace saidwall |4said reinforcement |5 and said top I6.` The web |8= is arrangedalong the vertical center line of the ,5 members II, I4, I5 and I6. Thewebs Hand the wall I4 are further interbraced by horizontal webs 20.

The upper side of the top plate I6 is' adapted for the securementthereto of a bending die 2|, ..250 as by means of bolts 22. The freeedge of the top I6 running parallel to the wallA I4 is reinforced by anupwardly directed ange 23. `The latter has screw threaded therein bolts24 serving for the adjustment of the"`die 2|. The die -55 plate l l.

2| and its'use will be described more fully later Secured to the bottomplate is a pair of gibs 25 which run parallel to each other and to thewall I4. Another gib 26 is secured to the wall I4 and extendshorizontally on both sides of the web |8.

A pair of generally U-shaped structures 21 engage with mating gibs 28and 29, respectively, the aforesaid gibsl 25 and 26 so that thestructures 21 are slidably guided on the structure formed by the plateII and the wall I4. Each structure 21 has a vertical web 3|) carryingthe gibs'29, a lower horizontal arm 3| of considerable length carryingthe gibs 28 and a short horizontal upper arm 3|. The lower arm'is in theform of a circle segment and has secured to its. periphery a rack 32. I

Secured to the underside of the plate I I and arranged inthe well I2 isan electric motor 33 which `through gears 34 drives a short shaft 35rotatably supported in bearings 36 secured to -the top of the plate IIand which is controlled by the diagrammatically illustrated switch 33'.The shaft extends parallel to the hereinbefore described gibs 25 and isarranged co-axially with a pair of screw threaded shafts 31 the outerends of which are supported rotatably but axially immovably in'bearings38 likewise secured to the The vscrew threaded portions of the shafts 31engage nut members 39 secured to the arms 3|. Between the inner end ofeach shaft 31` and the `adjacentouter end of the shaft 35 is arranged acoupling 40. The two couplings 40 are independently controllable, as bylinkage and lever systems 4|, 42. l

- -f A pair of generally horizontally arranged arms 43 `have their inner'ends journalled rotatably about'a vertical axis to the arms 3| and `3|of the` structure 21 at 44.l At some distance from the journal 44, eacharm 43 rests by means of rollers 45 on the top surface of a horizontalextension 46 of thearm 3|. Each arm carries a motor 41 which throughgears 48 drives a pinion 49 engaging one of the racks 32. The motors 41of the two arms are controllable independently of each other by a pairof control means diagrammatically illustrated at 50'in Figure 1. Eacharm 43 extends outwardly beyond the roller support 45, 46 and has itsvextended portion' provided with apair of horizontally spaced verticalgibs 5|."The gibs 5| are engaged by correspondingly shaped gibs 52provided on a horizontal beam structure 53. Each beam structure 53carries an electric-motor 54V which through `gears 55, drives ahorizontal shaft 55 rotatably supported in bearings 51 on downwardextensions 58 of the beam structure 53. The shaft 56 has secured theretonear each of its ends a Worm 59 which is in driving engagement with aworm wheel 60. Each worm Wheel 60 is held between lugs 6| of theextension 58 and is secured to a screw threaded shaftr62.TheL-screwwthreads of the shaft *62 engagethe correspondingly screwthreaded interior of a lug 63 formed integrally with the respective arm43. Here again each of the two motors 54 is independentlyscontrollableby a pair of control means 64 diagram-- matically illustrated inFigure-1.

Each beam structure 53-'carniesin bearing's'165' rotatably but axiallystationarily a second "shaft B6 which is screwthreaded:foversthe/greater part of its length. The shaft 65 is indriving connection with a motor 61 by means of gears. "'T-he motor El'is supported by the respective beam 'structure 53 :controllable:independently f the corresponding motor on the other arm .by the`control means GBL-'diagrammatically shown iin Figure l. A

' Acpairaoffsleds '1n rare 'slidingly supported by gibs :1l lformed:thereon and .correspondingly shaped guideways 12 of the beam'structures53. lEaclfiisled i110 is in.fscrew':threaded engagement Vwithcwonesofthe/shafts :15.6 `so *that -rotationfnf the-latter causes'fthe sled tomove along-its suptporiting beam structure 2:53.

nf-hydraulic cylinder 13 isjOurnalled at'w'M fto zlugs'11.1.5crintegrally:securedtoza the. asled 119. vThe -opposite end vofthe :cylinder 13 `has' rollersfI-S which :irun on :a =rsegment shaped:portion 11 of fthelisled`1'll. iA piston `18 in' the interior of A.theicyl-inclerzzlS'sis connectedfvto a rod 19 `which carries a vise llswingably .around-:anhorizontal bolt 581|.

Thevisess `are .adapted for'rm fbut releasable engagement :ofrronexendeach Yfof a workpiece'BZ by 'means of jaws '83. .Thetdrawings'show.l an angle section workpiece but. itshouldv be understood:that a ygreat variety `.pi'ffcross'-:sections may ibe bentfbyztheillustrated machine. Of. course, 'the jaws of the '.vi'ses 8l'andtheidle: 25Il'xlf1ave 'lto` :be shapedzinraccordancewiththecross-section oflthe workpiecezato be'made.

Pressure Amedium may be :admitted to andadis- ``charged `-from thecylindersJS-by means o'f the zpiperlines- Stand .thezvalvesflB `andfthereturn V.of -the'pistons ymayiber effected yby .springsul #The :pressureimediunixis supplied :'by the A.pump :ll-'l driven by motori88. Theldrawing clearly :shows the :substantially symmetrical constructionofffthel machine Arela- '.tive'to fa verticaletransverse .planeand 4.the.proiy-.ision Iim most elements' in :.pairs.-.even though,.ticcasionally `for,rsimplicityssake, one .of the.Ielements'onlyqhasbeen `'referredto in fthe foregoing description.

:The Aoperation of the newrmachineunder-dif- .ferent fconditionsfwill.nowibel briefly described.

-If,:. as -in Lthe 'illustrated embodiment, the fdie lfhasazworkingsurfacewhlich .is curved in: one pl'anelonly andwhichisesymmetrical to a `center =line,':theidie .is placed inthe:machine. sof'l:hat its centerline coincidesr iwith the. center linefofthemachine. .'Ilhe .location of the journals #Agris adjustedbysmeans-.o'f the motor 33 and the .transmissions .driven thereby. 'Thefs'leds i 10 are movedbyzmeans of Ithe motors 61 along the beams 53stepositions -at which the `viseswall arecat-a distancel from each otherv:equaling about fthe length :of .theI workpiece :82. .Alsowthefheightof the visesy is adjusted so that they are at the same level with theworking surface of the die 2l; this adjustment lis done by the motors 5Aand the transmissions between them and the beam 53.

5 After these adjustments the workpiece 82 isplaced with its ends in theVises 80 and secured therein while the arms 43 are in the positionillustratedfinfliigure 1. Pressure medium is now admitted'to thecylinders 13 so 'thatthe worklo piece 82 is stretched and, while theworkpiece 'sis under tension, the arms 43 are swung toward `each otherabout their pivots 44 by means of 'their motors @1, the transmissions48, the pinions .lfllgfzand the vracksflil The tension of the work-*bend-ing "operation by reference to a pressure .gaugeattachedtothecylinders 13, to any part of the conduits for the pressure medium or tothe-pump 81.

If the working surface is more complicated fthanizillustratcd, for:instance longer, non-'symcmetrical; and inradditioncurved lin verticaldirecvtion; differently: oncboth Ysides of its middle plane, then eacharm andthe elementsattached thereto-:havelto'be .moved independently ofeachother 4by means ofiithe--hereinbeiore 'described motors v:andcontrolmechansmsm64, 69. For instance,

one vise fall. may be moved-upward by. means of the motor .5A fwith itssupporting. beam-53rand esledflftothe position illustratedby-dot-and-.dash 'ilinesinjzFigure 2,lwhereasfthe other vise fallmay.belkcpt .dependentali-pon' the .form :of the die, fon

the original level:.or.may even ,bemoved'downwa-rdly: :by -itsfmotorr54- 'Similarlyfeach. ofthefarms 133 may be independently .movedaccording to laws .dictated by the formlof the die. This:independentfmeve- .mentfdoes notfonly sapply. to the .swinging Labout.-the.journa1s 44, :but even the location-offthe 40 rjournads maybe-'changedduring .thefbendingand stretching '.operation.

No attempt is made to illustrate-and .describe .inf-.detail i Aany n ofthoseamany. .forms which :may .be made on. the newmachlineby proper.coordina- .tionf of the different ...independent Emovements. Anybodyskilled in the art knows theproblems ,and ...will .easily .recognizemtheIpossibilities .off ered l,bythenew machine and how. to operate it soras .to cope. with .any .one ofsuch` problems.

.Theinvention is vnot: restricted to thedetails .oftheillustratedembodiment. For instance, .oer-

tain parts of the machine may be omitted while nthersmay. .be.,substituted. by equivalent. means. Consequently, .protection .soughtfor the .inven- .55 tion as broadly as covered by the spirit-andy the.language of .theattached claims.

Whatis .claimed ist 1. In astretching. andy bendingmachine, a basestructure, means on saidbase structure for. sup- 50 ,portinfz an armswingable .about an axis, atormingdie stationarily supported on saidbase structure inthe region ofsaid axis, an elongated .structurecoextensive with at least a major ,portion of 'said armand-'supportedthereby moi/ably' back and forth vin a fdirectionjgenerally,parallel tosaid "axis of rotation, a sled slidable on said structure yback-an'dfforth'radially with respect to said' axis, means supported on saidsled for firmly holding -a-woi'*k-piece,4 and means for `holding aworkpiece .at a distance. from lthe -pointheld bythe aforesaid. holdingmeans.

i2.In a stretchingr and bending machine,1a base 'structure-:means onrsaid base structure for supporting an arm swingable about anlaxis, a'form- :ing diestationarily supported on saidf-lbase'structure in theregion of said axis, an elongated structure coextensive with at least amajor portion of said arm and guided thereon movably back and forth in adirection generally parallel to said axis of rotation, a sled slidableon said elongated structure back and forth radially with respect to saidaxis, means supported on said sled for iirmly holding a workpiece, meansfor holding a workpiece at a distance from the point held by theaforesaid holding means, a motor supported by one of said arm and saidelongated structure, a transmission between said motor and other of saidelongated structure and said arm so as to move said elongated structureon said arm during the operation of the machine.

3. In a stretch forming machine: a support and a forming die mountedthereon, a pair of means for rmly holding a workpiece in two spacedregions thereof and for stretching the workpiece between said means, anarm rotatable about an axis relative to said support, means on said armfor supporting only one of said holding means movably in a directionextending about parallel to the axis of rotation and at a distance fromsaid die mounted on said support, while said workpiece is held by saidpair of holding means in stretched condition in contact with said die.

4. In a machine for stretching and bending, a base, and a forming diesupported thereon, a pair of devices for immovably engaging spacedpoints of a workpiece and for stretching it between them, means forsupporting said devices on said base, said supporting means beingadapted for moving the devices independently of each other in threediiTerent directions relative to said die supporting means whichdirections define co ordinate planes of a spacial coordinate system,while said workpiece is held by said engaging devices in stretchedcondition in contact with said die supported on said base.

5. In a machine for stretching and bending, a base, and a forming diesupported thereon, a pair of devices for immovably engaging spacedpoints of a workpiece and for stretching it between them, means forsupporting at least one of said devices on said base and for moving itindependently of the other device in three coordinate planes relative tosaid die supporting means while said workpiece is held by said engagingdevices in stretched condition in contact with said die supported onsaid base.

6. In a stretching and bending machine, a supporting structure, aforming die supported thereon, a pair of arms swingable about generallyparallel axes relative to said structure, means on each of said arms forgripping and stretching a workpiece, a supporting device and poweractuated means for each of said gripping means adapted for moving thelatter in the direction of its respective arm, and power meanscontrollable independently of said first-named power operated means formoving said gripping means relative to said supporting structure in adirection generally parallel to the direction of said axes, while saidworkpiece is held by said gripping and stretching means in stretchedcondition in contact with said forming die.

7. In a machine for stretching and bending, a base, a forming diesupported thereon, a pair of devices for holding and stretching aworkpiece between them, means for supporting at least one of saiddevices on said base for movement independently of the other device inthree intersecting directions defining three coordinate planes, andthree separate and separately controllable motors each of which isadapted for moving the respective device in one of said differentdirections while the workpiece is held by said stretching devices incontact with said forming die supported on said base.

WILLIAM A. WEIGHTMAN.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 537,550 Schacht Apr. 16, 1895716,555 King Dec. 23, 1902 957,200 Gail May 10, 1910 1,447,299 FreemanMar. 6, 1923 1,710,261 Kellogg Apr. 23, 1929 1,968,010 Bailey July 31,1934 2,155,160 Bruno Apr. 18, 1939 2,190,423 I-Ienricson Feb. 13, 19402,255,867 Wisckol Sept. 16, 1941 2,305,850 Drysdale Dec. 22, 19422,357,027 Seifried Aug. 29, 1944 2,370,329 Seifried Feb. 27, 19452,431,173 Hawkes Nov. 18, 1947 2,446,089 Hochreiter July 27, 1948FOREIGN PATENTS Number Country Date 482,769 Great Britain Apr. 5, 1938

